The Thin Blue Line
by hiddenhibernian
Summary: There is a thin line between order and chaos, the ordinary lives most of us lead and the dark forces that want to destroy them. The Aurors will defend Muggles and wizards alike, to the best of their ability - the only problem is that they're ordinary people, with weak spots and pets and families waiting at home. How can they win against someone like Bellatrix Lestrange?
1. Chapter 1

**As always, my sincere thanks to williamsnickers who puts so much time and effort into editing. Any remaining mistakes are my own. This was originally written for HP Get Lucky on LiveJournal.**

* * *

 **The Thin Blue Line**

 **Chapter 1**

 **-oOo-  
**

"You must always be vigilant! Constantly!" The instructor banged his fist on the battered desk, paying no attention to the creak that followed. He was busy eyeing the new recruits, dwelling for a moment on anyone who didn't look away quickly enough until they squirmed in their seats.

As wizards went, he shouldn't have been very impressive – a few limbs were missing, and he moved like a scarecrow rather than a leopard waiting to pounce, but there was something about him that kept the class pinned to their seats. He hadn't bothered to introduce himself; perhaps he thought they ought to know him already.

This was the first day of the Auror training programme – most of them were struggling to remember the way to the loo, never mind identifying the gnarly wizard before them.

"You there!" he barked.

The whole class froze in panic. The only sound was Bletchley's heavy breathing – how he had got through the physical exams was a mystery (made somewhat less baffling once Bletchley let it slip his uncle was the Permanent Under-Secretary in the Department of Magical Law Enforcement).

Alastor swallowed as he realised he was the unlucky object of the instructor's attention. "Yes, sir," he managed.

"How would you spot a Dark wizard? What's your name, anyway?"

He did know the answer to the second one, at least. Fortunately, he had also spent some time considering the first question.

"Alastor Moody, sir. I would be alert for signs of Dark magic, and compare the suspect to descriptions of known Dark wizards. And witches, sir."

"Hmf. Mighty glib for someone just through the door – I know your mother, of course. So, young Mr Moody, can you spot any gaps in your approach?"

Everyone in the Auror office – and the Department of Magical Law Enforcement – knew his mother, and many of them had known his father, too. Alastor had always realised he would have to prove his worth, but he hadn't expected to start on his very first day.

"Polyjuice, sir. Or any other charms or potions used to disguise one's appearance."

"Anyone else? Come on, don't be shy – surely Mr Moody isn't the only recruit with a bunch of Outstanding N.E.W.T.s in his back pocket?" The instructor let his eyes wander around the room. Alastor relaxed minutely, before he realised he should have mentioned Sneakoscopes – and detection charms. How could he have forgotten?

Someone else on the other side of the room was suggesting the Revelio charm – Alastor vaguely recognised her from Hogwarts. Ravenclaw, a year above him, if he wasn't mistaken.

"Excellent choice. Homenum Revelio, flick your wand, and Bob's your uncle. Then what?" the instructor barked.

"Er..."

"Has no one else got a tongue in their head?"

Alastor decided he had made his contribution – he wasn't going to offer his head for washing without being called upon again.

Fortunately, he was left alone. "Of course you don't, you're about to become Aurors," the old wizard said, sarcasm rolling off his tongue. "You'll Apparate somewhere, shoot off a few spells before apprehending some scoundrel who belongs in Azkaban, and return to fetch your medal. Right?"

Alastor was desperately hoping the heat in his cheeks wasn't showing. That was roughly the way he had been imagining things would go.

"The problem with that is that you don't know where to Apparate before it's too late, and once you get there, you don't have a clue whether someone is an innocent bystander or a perp. If you actually manage to catch someone, there's this little thing called 'evidence' the Wizengamot is quite keen on. Not to mention that a large bag of Galleons will get most charges squashed. Didn't think it happens? Think again."

Alastor knew it did, but he was still shocked to hear someone acknowledge it so casually.

"You're fighting evil. Pure evil, don't forget that – once you've seen a few of the things I have, there will be no doubt in your mind. There will probably be a few things you'd rather forget as well, but that's the way it goes. It doesn't mean will be easy, but as long as you remember why you're doing it, you'll be alright. Mostly."

Alastor looked where the instructor's missing right hand should have been, and wondered exactly what he meant by 'mostly'.

* * *

It was Kingsley's third time doing The Speech.

He was still expecting Moody to come charging through the door and growl at him to shut up and get back into his seat. It hadn't happened so far – to the surprise of his colleagues, Moody had stuck to his decision to retire while he still had most of his limbs. Bar the occasional emergency callout to subdue stray cats and charity collectors, the Auror Office had to get by without him.

Which left Kingsley with the unenviable task of addressing the new recruits.

He remembered his first day as if it had been yesterday – Moody barking "Constant vigilance!" while letting his magical eye room around the room had that effect on most people.

Kingsley felt decidedly average by comparison, but he still had to do it.

There was a fine line between telling his new troops what they needed to know and causing them to run off screaming, never to be seen again. Mad-Eye had never had many vanishing acts – maybe they had been scared stiff, unable to move from their seats.

Maybe he had just been better at it.

Kingsley had lost three last year and five the previous one. He couldn't afford to lose any of this year's intake – they were stretched to the limits after the mass breakout from Azkaban, and it wasn't going to get any easier. Things were about to become very bleak indeed, and they needed Aurors who could stand their ground against Voldemort and his forces.

Kingsley realised he had resumed talking without noticing.

"We need you, it's as simple as that. The wizarding world is crying out for people willing to stand between them and the darkness. It takes courage to stand firm when you're faced with the worst magic can throw at you – the average witch or wizard isn't cut out for it. They need you to protect them from what they can't handle."

There was a slight swell of squared shoulders and straightened spines at that – this year's intake didn't feel average.

They never did – Kingsley had thought he was the bee's knees when he had turned up for his first assignment, armed with no less than three wands and a dozen potions squirrelled away in his pockets.

"To be able to protect your fellow wizards – and Muggles, who deserve exactly the same protection you would extend to a wizard – you will go through a training program renowned in the Wizarding world for its stringent entrance requirements. I advise you not to relax now that you're here – completing the program will be far more taxing than anything you have encountered previously."

They looked like Hogwarts students to him, teenagers who should be flirting and playing Quidditch instead of studying Stealth and Tracking. None of them could even remember the first war – they had no idea what they were in for.

Kingsley had been the same, once.

Buried somewhere at the back of a drawer in his flat, there was a photo from a particularly good night at the Leaky Cauldron. The sideburns alone would make Tonks squeal with laughter, before sporting the same hairstyle every time she ran into him for weeks. Even the too-wide ties and horrible floral patterns couldn't disguise their youth – every time he looked at Lily and James, Kingsley wondered how they had been allowed to join the Order.

He knew, of course: for the same reason as he had a room full of shiny new recruits barely out of the school robes. No one else would join, so they took the young people, who didn't know what they were signing up for.

Kingsley had been a slow learner – he had sat out the war getting through the abridged training program, graduating a few months after the Hallowe'en that had seen the end of Lily and James and, for a long time, the being who called himself Voldemort.

He had been an Auror for more than three years before he realised what it truly meant to stand between ordinary wizards and the darkness.

* * *

"Get down!" Kingsley spotted the incoming curse at the last moment, pushing Savage out of the way. The latter yelped and the air filled with the smell of singed flesh, but he didn't seem to be seriously injured.

"I can't Apparate! We're stuck here!" Savage had spent most of the three months he had been seconded to Kingsley pointing out the obvious. Crouching in a suburban garden, trying to avoid spells coming from several directions, was not the time to take him to task – instead, Kingsley desperately tried to find some cover.

It was a brand new estate and the trees were only saplings. Their assailants must be hiding in one of the neat detached houses, because there was no other shelter. Kingsley kept moving, casting spells and blocking curses as he scanned their surroundings.

There! A shed, at last. He looked over his shoulder to tell Savage to follow, only to discover his partner had folded into a position that definitely wasn't on the curriculum of the training program.

Kingsley's wand moved in three economical slashes – one flung the door of the shed open, the second transported Savage inside and the third, once he had leapt inside, warded the door shut.

Kingsley slid down with his back against the wall, already planning his next move while checking Savage's pulse. It was steady, and a few diagnostic charms revealed he was unconscious, but not in a critical state.

Yet.

Their attackers had obviously seen where they had gone – the lack of renewed hostilities was ominous. Kingsley briefly considered sticking around to see what they would do, but common sense won out. An injured colleague was more important, and he could return with reinforcements anyway.

Digging out the Portkey in his hollowed-out boot heel, Kingsley cast another spell to make it look like they hadn't abandoned the shed. Satisfied he could return with significant backup as soon as he had dropped Savage off, he tapped the old shirt button he used for emergencies.

Nothing happened.

Kingsley's hands were entirely steady as he pulled off his other boot, removing the heel to reveal a battered cigarette lighter.

On his first attempt to light it, nothing happened. The second time the flame flickered and tied. Kingsley's face didn't move a muscle.

The third time the flame held true, and Kingsley stared into it as if it were the most important thing in the world. He kept on staring as the allotted twenty seconds for emergency backup to be dispatched elapsed.

A whole minute went by.

The whole shed shook and it briefly filled with an orange light, but Kingsley's wards held. He knew they wouldn't last long in the face of a determined attack, however, and swiftly moved to strengthen them.

Whoever they were fighting knew enough to block the Auror Office's emergency measures. The anonymous tip-off that had sent them into Surrey now seemed deeply suspicious, and one part of Kingsley's brain was listing all known Death Eaters still at large. He saw to Savage – there was no way of evacuating him at the moment, but at least Kingsley could ensure his airway was unobstructed, and protect his body from discovery.

He also pocketed Savage's wand – a spare one had got him out of trouble before.

The next thing he did was to close his eyes, allowing his face to relax. After half a minute, a wisp of silver smoke finally appeared from the edge of his wand, and with intense relief Kingsley saw it form into a lynx.

"We're trapped in 68 Kenmore Gardens, Godalming, Surrey. Under attack from several unknown assailants, Savage injured. Immediate backup requested," he told it with the same measured voice as he dictated his case reports.

The lynx took a leap and disappeared through the wall, no more troubled by the wards than it would be by any curses the opposition may throw at it. It would get to the Auror Office, but when?

It would take at least half an hour, by Kingsley's reckoning. He had better do something before then. A flick of his wand revealed the nearest human body was within five feet of the shed, much closer than he had hoped – a quick transparency charm showed a more immediate threat heading their way: Fiendfyre!


	2. Chapter 2

**Chapter 2**

 **-oOo-**

Kingsley had only seen Fiendfyre in training, and even then it had scared him witless. Ordinary fire was bad enough for anyone who had seen the aftermath of a major incidence, but fire that could not be contained or stopped let loose in a Muggle neighbourhood...

Up until then, he had fooled himself he had the situation under control. Faced with Fiendfyre tearing towards the flimsy shed he was hiding in with the unconscious Savage, Kingsley realised they might be dead by the time his precious backup arrived.

All of them, not just Savage and himself.

In the general chaos, Kingsley hadn't noticed any Muggles in the locality, but there was no way all the tidy, suburban new-builds were empty during the day. There would be young children around, together with their carers; bed-bound office workers who had called in sick for the day; tradesmen and cleaners plying their trade while the residents were at work.

None of them would have been expecting a pitched battle – Kingsley hadn't either, but at least he had the means to defend himself.

He was supposed to know what he was doing – Moody would have him strung up for this if he ever found out, and rightly so.

One did not walk into an ambush and ignore the potential casualties among civilians, no matter how reckless one may be on one's own accord.

There was no official Auror code, but the same philosophy had been drummed into almost all of them: the whole population was under their protection, magic or Muggle. Staring at the Fiendfyre consuming every scrap of vegetation in its path to get to its prey, Kingsley understood the extent of the burden he had taken on for the first time.

Muggle police officers were protected by the laws of nature; gravity, thermodynamics and the rest.

The criminals he faced were experts at using magic to push the boundaries of what was possible to the other side of the abyss, where everlasting fire and resurrected dead bodies came from. There was nothing they couldn't do, as long as they were skilful skillful? enough.

Kingsley was paid to work forty hours per week, including lunch and tea breaks. How was he ever going to compete with that?

Time had slowed down to a creep while Kingsley had his epiphany, but thankfully he wasn't completely incompetent – he had been preparing their exit to be timed precisely when the Fiendfyre hit the shed. As soon as the first flame licked the outside wall, Savage was catapulted into the nearest garage like a one-man stretcher catapult. Kingsley leapt the other way in a blaze of curses, targeting the approximate location of the origin of the Fiendfyre.

The shed turned into a blaze too bright for human eyes to watch. There was a muffled shout somewhere close – a hit!

Kingsley lost sight of the fire for a second, realising his mistake as his eyebrows were singed off by a snake snapping at him inches from his head. He dove out of the way, desperately trying to outrun the curse. Using his wand to speed up his progress, he managed to shake off the Fiendfyre temporarily, only to see it setting a house ablaze instead.

He coughed like his lungs were on fire, too, and got a fist in the face for his troubles. He rolled with his assailant in a mess of limbs grappling for purchase, hitting anything within reach. Suddenly, Kingsley couldn't breathe – he was aware of bumping into something, but he couldn't tell what, or even if he still was moving.

The light was fading.

He hoped he would die before the Fiendfyre got to him – of all the ways he had seen people die, death by fire was the worst.

There was noise somewhere, far away, and then Kingsley was jerked out of his bubble.

"You lot get the Muggles, I'll deal with sunshine here!" Mad-Eye Moody barked, and Kingsley got an eyeful of the craters and lines making up his scarred face. As soon as his eyes had flickered open Mad-Eye's magical eye zoomed in on him.

It was a hell of a way to wake up, but at least Kingsley was certain he was still alive. He couldn't see either side of the great hereafter greeting newcomers with anything like Moody, and in any case he, unlike Kingsley, was far too smart to get himself killed on what should have been a routine assignment.

"Got all your limbs, lad?"

Kingsley nodded, not trusting his voice yet.

"Smoke inhalation? Got someone from St. Mungo's looking at Savage, I'll get her to come over soon."

"Who?" Kingsley found his voice, although it sounded like he was smoking forty a day.

"Do I look like a Healer directory to you?"

"No, the perps."

"Oh, them. No one on our books. Small-time crooks, by the look of it. Perkins has a Death Eater cousin on his mum's side, otherwise nothing of note."

"My Patronus?"

"You sent one?" Moody's expression suggested Kingsley had risen somewhat in his estimation, which was lucky as his current position probably was on par with things that had never seen daylight because they lived at the bottom on the ocean.

"Couldn't Apparate –"

"Yeah, we noticed – someone taught those lads a trick or two. We'll see what we get out of them in interrogation. It was lucky we picked up a Muggle emergency call, or you would have been toast. Now, since you're not about to die on me, you'll have to excuse me – I've a scene to secure, and it's a wee bit messy at the moment." Moody stalked off, wand at the ready, barking orders to half-a-dozen people.

Kingsley propped himself up against the wall he had crashed into. No doubt there would be an excruciating debrief waiting at headquarters, scrutinising every mistaken move he had made, but he knew he was a lucky bastard to get out of this with only a bollocking.

This was what they didn't tell you in training: sometimes, it was just down to luck. To stay alive, you needed to be lucky all the time – all the enemy needed was one chance, and you would be swept off the ground and handed over in an urn to your relatives.

Unfortunately, you had to learn the hard way – no matter how hard someone tried, they could never tell you what it felt like until you had been there.

Now Kingsley had, too, and every rasping breath felt like a shout of triumph.

* * *

Kingsley must still be a fool, no matter how much he had learnt since he was sitting where the recruits were now, because he still tried to tell them what had eluded himself so many years ago.

"There will be a time when your back is against the wall, when you're regretting not taking out the life insurance your cousin Phil was trying to flog to you. It could be anyone – a dragon-parts dealer with a knack for the Dark Arts, or a renegade Death Eater. Somehow, someone will have you by the short and curlies, and you will have to figure out how to get out of there alive. Or die trying – that's an option too."

Kingsley took a sip of water from his hip-flask, ignoring the thoughtfully provided carafe and glass. Mad-Eye may have retired, but if he got word Aurors were drinking unverified liquids, there would be hell to pay.

"The thing is, there will always be someone who is better than you. Some of them even trained with us. They know all the tricks, and they don't have to play by the rules like we do."

* * *

"But sir –" Someone at the back raised their hand. "How do you ever catch any dark wizards, then?"

"Flynn, is it?"

The student blushed, and Harry took pity on him. "We seem to be doing fine, but thanks for asking. What I'm trying to get across is that, no matter how good you are, there will come a time when the chips are down and you have to fly by the seat of your pants to get through. We can't train you for every contingency."

He looked down towards the end of the room, but it wasn't the neat rows of students and the walls painted in standard-issue Ministry beige he was seeing.

"It's pure luck that I'm standing here, lecturing you on how we brought Voldemort down, rather than some Death Eater haranguing you on the evils of Muggle-borns."

All the oxygen seemed to have been sucked out of the room. Saunders was still taking notes, though, Harry noticed absently. There was always one.

"All of Dumbledore's plans, all the efforts of the Order of the Phoenix would have been in vain if I had spotted Snape in the battle. I would have killed him. Or someone else might have killed me, easily. I don't think anyone who wasn't there realises how very close it was. One misdirected spell, and I would have been history."

He noticed he had started pacing around the room, as if he were trying to walk away from the memories of Hogwarts turned into a battlefield.

"It wasn't due to luck that we won, of course. Plenty of people you've never heard of died to bring Voldemort down. The Battle of Hogwarts is famous because it was the last one – it doesn't mean the other ones didn't matter."

Mad-Eye Moody may have died in a skirmish to let Harry escape Privet Drive, but it didn't change the fact that he had been one of the reasons they had won the war. Tonks and Kingsley, Frank and Alice Longbottom, Hestia Jones and many others had been trained by him in the best traditions of the Auror Office. They had held the line against the darkness when the Ministry had failed.

"It wasn't luck that had Hermione – the Minister, I should say – brew Polyjuice as a second-year student. Dumbledore didn't put his feet up and hope for the best – he staked his reputation and then his life on his hunches turning out right, because that was the only way he could see to defeat Voldemort."

None of the students flinched at the name, like wizards of Harry's generation still did. He swore they got younger every year.

"We've got a job to do. It's up to us to prepare as well as we possibly can for the task facing us. Then we have to roll with the punches and deal with whatever is thrown at us, whether luck goes our way or not."

The clock on the wall struck twelve. Harry remembered he was supposed to be doing the introductory speech for the new recruits, not reflect on the nature of luck. "That's why you're here: to prepare you for what's waiting out there. Spend your time on the training program wisely."

To their credit, the students didn't move until he nodded to them – then they spilled out into the corridor in a chattering stream, bursting with energy built up from listening to Harry's monologue for an hour.

They would be all right. They would learn, like they all had learnt, and hopefully, they would come out with all their limbs on the other side of that youthful enthusiasm that always gave Harry a headache.

Harry nodded to the portrait of Venusia Crickerly on the wall and sauntered down to the Ministry canteen for lunch. Next week he would tell them about risk assessment, and why seasoned Aurors always checked the menu before venturing into the canteen.

 **THE END**


End file.
